When I: Multiply x by a # > 1, the image gets wider, and stretches side ways by the scale factor.
Multiply y by a # > 1, the image gets taller by the scale factor. Multiply x by 0<#<1, the image becomes thinner, slimmer and less wider by the scale factor.
Multiply y by 0<#<1, the image becomes shorter
When I multiply both x & y by the same numbers, the image changes its size and is similar by the scale factor.
When I multiply both x & y by the different numbers, the image is not similar.
2.3 statements
When I: Add to x, the image is congruent, and moves to the right the number I added (addend), but doesn’t change its size.
Add to y, the image is congruent, and moves to the up the number I added (addend), but doesn’t change its size.
Subtract from x, the image is congruent, and moves to the left the number I added (addend), but doesn’t change its size.
Subtract from y, the image is congruent, and moves to the down the number I added (addend), but doesn’t change its size.
Stretching and Shrinking
Big IdeaMany things in our world are mathematically similar and we can use this to understand and describe the world around us.
Essential Question # 1 - How can I make a drawn figure larger?
1.1 Stretching a Figure -
Mathematical Reflections p.13 -
Essential Question # 2 - What is the same and what is different about “similar” figures?
2.1 Drawing Wumps -
2.2 Nosing Around -
2.3 Making Wump Hats -
Mathematical Reflections p.27 -
Essential Question # 3 - How can I use math to check if two figures are similar?
3.1 Identifying Similar Figures -
3.2 Building with Rep-tiles -
3.3 Subdividing to find Rep-tiles -
Mathematical Reflections p.40 -
Essential Question # 4/5 - What types situations can I use my similarity ideas to solve?
4.1 Using Similarity to Solve a Mystery -
4.2 Scaling Up -
4.3 Making Copies -
4.4 Using Map Scales -
Mathematical Reflections p.58 -
5.1 Using Shadows to Find Heights -
5.2 Using Mirrors to Find Heights -
5.3 Using Similar Triangles to find Distances -
Mathematical Reflections p.74 -
Stretching and Shrinking Vocabulary
2.1 statements
When I:
Multiply x by a # > 1, the image gets wider, and stretches side ways by the scale factor.
Multiply y by a # > 1, the image gets taller by the scale factor.
Multiply x by 0<#<1, the image becomes thinner, slimmer and less wider by the scale factor.
Multiply y by 0<#<1, the image becomes shorter
When I multiply both x & y by the same numbers, the image changes its size and is similar by the scale factor.
When I multiply both x & y by the different numbers, the image is not similar.
2.3 statements
When I:
Add to x, the image is congruent, and moves to the right the number I added (addend), but doesn’t change its size.
Add to y, the image is congruent, and moves to the up the number I added (addend), but doesn’t change its size.
Subtract from x, the image is congruent, and moves to the left the number I added (addend), but doesn’t change its size.
Subtract from y, the image is congruent, and moves to the down the number I added (addend), but doesn’t change its size.